Refrigerating apparatus



Sept. 17, 1957 D. J. TIMMER 2,306,359

REFRIGERATING APPARATUS Filed May 18, 1956 3 Sheets-Sheet l IN V EN TOR.

I flaridd. 77mm HIS ATTORNEY D. J. TIMMER 2,806,359

REFRIGERATING APPARATUS Sept. 17, 1957 Filed May 18, 1956 3 Sheets-Sheet 2 v ll 1 20 INVENTOR.

7 5 By David J. Tim-mar Hi5 ATTORNEY Sept. 17, 1957 Filed May 18, 1956 D. J. TlMMER 2,806,359

REFRIGERATING APPARATUS 3 SheetsSheet 3 BY? z Hi5 ATTORNEY David J. Timmer United States Patent O i 2,806,359 REFRIGERATING APPARATUS David J. Timmer, Dayton, Ghio, assignor to General Motors Corporation, Detroit, Mich a corporation of Delaware Application May 18, B56, Serial No. 535,905 7 Claims. (Cl. 62-117.4)

This invention relates to refrigeration and particularly to a method of and means for providing in a refrigerating system having a combined roll-forged condenser and evaporator member therein a refrigerant restrictor.

It has recently been proposed to form a capillary passage within a roll-forged member having portions thereof forming two or more elements in a refrigerating system which passage provides a refrigerant restrictor for the system. This proposal is difficult and expensive to carry out and has resulted in loss due to a considerable number of roll-forged members being rejected and/or scrapped. Problems of properly dilating and flushing out a capillary passage formed in a roll-forged member therefor renders it desirable, at least temporarily, to provide a cheaper and novel method of and arrangement for incorporating a separate capillary restrictor in the construction of a roll-forged member of the type disclosed in the patent to James W. Jacobs and Richard E. Gould, No. 2,779,168 granted January 29, 1957, entitled Refrigerating Apparatus and assigned to the assignee of this application to render the same immediately practical for use in refrigerating systems.

An object of my invention is to provide a low cost practical combined unit or member forming a plurality of heat exchanger elements of a closed refrigerating system with a refrigerant flow control means which while being separate from the member has a major portion thereof concealed therein.

Another object of my invention is to provide a refrigerant pressure reducer or restrictor for a roll-forged one piece member forming spaced apart heat exchanger elements of a closed refrigerating system which is contained in and extends along integral portions of the member from one element to another thereof for controlling flow of refrigerant therebetween.

A further object of my invention is to provide a member in a closed refrigerating system which utilizes all the manufacturing and other advantages derived from roll-forging the member into a one piece plate and the variou advantages of incorporating in the member a fixed tubular restrictor in such manner that the restrictor is in direct metal to metal heat exchange relationship with that portion of the member through which cooled evaporated refrigerant returns from the evaporator portion of the member to a motor-compressor unit of the system.

A further and more specific object of my invention is to sever or cut away a part or parts of a roll-forged plate member of a refrigerating system with a passage or duct therein for exposing ends thereof, to inserta predetermined length of tubing separate from the member into the passage or duct and to sealingly weld or bond ends of the separate tube to exposed ends of the duct to form a structural part thereof which tube has a major portion of its length concealed Within the member and has a substantially capillary inside diameter relative to other passages formed in the member for controlling flow of refrigerant between these otherpassages.

2,806,359 Patented Sept. 17, 1957 Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

Figure l is a front view of a refrigerator having a rollforged member of the present invention associated therewith;

Figure 2 is an enlarged fragmentary vertical sectional view taken on the line 22 of Figure 1 showing the mounting of different integral portions of the member upon or within the refrigerator cabinet;

Figure 3 is a rear view of the refrigerator disclosed in Figures 1 and 2;

t Figure 4 is a plan view of a trimmed roll-forged plate member after passages formed therein have been dilated;

Figure 5 is a view similar to Figure 4 with parts of the roll-forged plate member inwardly of its edges severed or cut away to expose ends of certain passages therein; and

Figure 6 is an enlarged view similar to Figure 5 showing a separate filter-dryer and capillary tube secured to the roll-forged plate member in accordance with my invention with the member ready to be bent to provide two or more elements of a refrigerating system.

Referring to the drawings, for illustrating my invention, there is shown in Figure 1 thereof a refrigerating apparatus including a refrigerator cabinet 10 having a plurality of insulated walls forming a food storage chamber 11 therein provided with the usual food supporting shelves. Chamber 11 has an access opening normally closed by an insulated door 12. A sheet metal refrigerant evaporator portion of a two-portioned integral rollforged member of a refrigerating system, associated with cabinet it? and to be hereinafter described, is located in the upper part of chamber 11. This evaporator forms walls of a freezing compartment in chamber 11 and is preferably provided with a front door (not shown) as is conventional in the art. The evaporator is adapted to chill air and cause its circulation throughout the interior of chamber 11 for cooling food products stored therein. The rear insulated wall 14 of cabinet 10 has an opening therein closed by removable inner and outer panels 16 and 17 respectively with loose or bulk insulating material 18 therebetween (see Figure 2) for a purpose to become apparent hereinafter. Cabinet 10 is provided with a machine compartment 19 below the food storage chamber 11. The refrigerating system associated with cabinet 10 comprises a sealing casing, containing an electric motor and a compressor driven thereby (not shown) and a roll-forged member having refrigerant passages contained therein and being bent or arranged to provide the system with an evaporator and a condenser. The casing 20 is mounted in the machine compartment 19 of cabinet 10 in any suitable or conventional manner and the roll-forged member is clamped to the casing so that refrigerant passages therein will be connected to and communicate with the interior of casing 20 as is shown and fully described in the Jacobs and Gould application hereinbefore referred to. In Figure 4 of the drawings I show a flat plate-like one piece rollorged member having various passages therein for refrigerant flow therethrough and this member may be produced in accordance with the roll-forged method described in the patents to George R. Long, No. 2,662,273 dated December 15, 1953 and Clifford H. Wurtz,

et al. No. 2,712,736 dated July 12, 1955, both assigned mined pattern of stop-weld material applied to the face of one of the plates for forming the desired shape of passage or passages between the plates. The superimposed plates are roll-forged together by passing them between a pair of heated rollers where their thickness is reduced and their contacting surfaces, beyond the pattern of stop-weld material, pressure forged togetherto provide a one piece homogeneous plate. After'roll forging the plates together the internal passages, determined by the design or pattern of the stop-weldmaterial, between the composite or one piece plate member are dilated by subjecting the same to a fluid pressure while the composite member is confined between suitable blocks or heavy plates in the manner fully explained in the Long patent. When the composite member comes out between the rollers and while it is being dilated it is in a flat form and is thereafter bent along certain predetermined lines to form one portion of the same into a box-like or U-shaped evaporator element which provides the walls of a freezing compartment and another portion thereof into a condenser element of a refrigerating system as disclosed in the Jacobs and Gould application hereinbefore referred to.

Referring again to Figure 4 of the drawings it will be noted that the pattern of the stop-weld material ap plied to one of the plates of the roll-forged plate member provides the same with two separate tortuous refrigerant passages 21 and 22. The passage 21 forms a refrigerant condenser and passage 22 provides the refrigerating system with a compressed refrigerant superheat removing or precooling coil or section. Trimmed as shown the roll-forged plate member is in reality in two integral portions 23 and 24 connected together by a web or leg 26 formed integrally on the member. The first portion 23 of the roll-forged plate member has passages 27 and headers or accumulators 28 therein providing refrigerant expansion or evaporating duct means. This evaporator portion 23 of the member is bent to form walls of a freezing compartment and is adapted to be moved into cabinet 10 through the opening in its rear wall, normally closed by the panels 16 and 17 and insulation 18 therebetween, so as to locate the evaporator freezing compartment in the upper part of the storage chamber 11. The sealed casing 20 is clamped to a lower part of portion 24 of the roll-forged member, as described in the Jacobs and Gould application hereinbefore referred to, and is moved therewith toward cabinet 10 to locate the casing in a supported position within the machine compartment 19. The passages 21 and 22 in this second elongated portion 24 of the roll-forged member provides a gaseous refrigerant condenser and a refrigerant precooler therein respectively. A passage or elongated duct 31 connects the outlet or lower end portion of condenser passage 21 with a refrigerant inlet passage 32 communicating with the refrigerant expansion duct means 27 and accumulator headers 28. This duct 31, as well as a refrigerant return conduit or duct 33 which leads from the evaporator to casing 20, extends through the web 26. It is to be noted that the passages 21, 22, 27 and 32 and the elongated ducts 31 and 33 are all of substantially the same size and internal flow capacity. This, as is well understood in the refrigeration art, requires a refrigerant pressure reducer or restricter to be provided intermediate the condenser 21 and the evaporator expansion duct means 27 and 28 in order to establish a pressure differential of refrigerant contained in the refrigerating system between different elements thereof. In order to prevent rejects and waste of rollforged members having restrictors formed integrally therein of the type disclosed in the Jacobs and Gould application and to preserve the advantages of such a rollforged member it is more feasible and less expensive to provide a refrigerant restrictor for a roll-forged member in another manner or method.

Referring now to Figure of the drawings, I sever or cut away a first section of portion 24 of the roll-forged plate member, inwardly of its trimmed edges, as at 36 with a lower part or segment of elongated duct 31 therein and a second section of portion 23 thereof as at 37 with an upper part or segment of elongated duct 31 therein. The opening 36 exposes the outlet end of condenser or passage 21 and a lower or first end of duct 31. The opening 37 exposes two other or second and third ends of elongated duct 31 respectively in the vicinity of the inlet 32 to the refrigerant expansion duct means 27. In accordance with my invention an element separate from the roll-forged plate is now to be associated with this member for controlling flow of refrigerant from the condenser portion to the evaporator portion thereof. This element may be a restrictor tube per se but I preferably provide a combined dryer-filter and restrictor tube element for the roll-forged member, the restrictor tube portion of which has an inside diameter which is substantially capillary in size as compared to the internal cross-sectional area of the passages or ducts 21, 27 and 31. The lower end of condenser passage 21, exposed by the cut-out opening 36 of the roll-forged member, is dilated with a suitable punch, tool or the like to a size capable of receiving an end portion of a dryer-filter 38 at one end of a capillary tube 39 connected or formed integrally with the dryer-filter. The opposite end of tube 39 is inserted into the first exposed end of elongated duct 31, at the opening 36, and is pushed or fedthrough this elongated duct .and through web means 26 until its one or upper end passes through the second exposed end of duct 31 and appears in the opening 37 in portion 23 of the roll-forged member. This end of capillary tube 39 is inserted into the third exposed end of elongated duct 31 or open end of inlet passage 32 of expansion duct means 27 and is Welded thereto to seal the joint therebetween. The end of dryer-filter 38 is also welded to the roll-forged member at the exposed outlet end of condenser passage 21 (see Figure 6). Capillary tube 39 is of a predetermined length and forms in the refrigerating system a fixed restrictor for controlling the flow of condensed liquified refrigerant from condenser 21 to the inlet 32 of expansion or evaporating passage 27 and headers 28. The tube 39 extends through web 26 within the passage or elongated duct 31 and can be simultaneously bent with this web means without danger of being pinched closed at the bend. The purpose of providing the opening 37 in portion 23 of the roll-forged plate member and of welding one end of tube 39 thereto instead of omitting opening 37 and welding tube 39 to the lower end of elongated duct 31 is to reduce the pressure of refrigerant flowing in the system at the exact point evaporation of refrigerant is to take place and to prevent liquid refrigerant from seeping back along tube 39 and evaporating in duct '31 at portions of the member outside the refrigerator cabinet and remote from the evaporator of the system. The enlarged part 38 of the combined element secured to the roll-forged member may contain a filtering screen and a refrigerant drying material such, for example, as granular calcium sulphate or the like. It is to be understood that the dryer-filter 38 may be dispensed with or that this element may be located elsewhere in the refrigerating system in which case the one or lower end of tube 39 would be inserted into the exposed outlet end of condenser passage 21, at the opening 36, and welded thereto. Thus I do not wish the present invention to be limited to the dryer-filter on one end of the capillary tube 39 since this dryer-filter is in reality merely an enlargement of one end of the tube. For this reason reference in the appended claims to one end of a tube being attached or secured to the outlet end of the condenser passage may or may not include the dryer-filter 38.

In a refrigerating system of the type herein disclosed refrigerant compressed in the sealed casing 20 is first directed out of the casing, through asuitable port opening, into the superheat removing or precooling coil or passage 22 in the-roll-forg'ed member and is then returned to the interior upper part of the casing '20. Refrigerant is again directed out of casing 20 into the tortuous refrigerant condenser passage 21 where it is cooled and liquified. Air circulating in the flue between the cabinet back wall and portion 24 of the roll-forged member is utilized to cool refrigerant in the superheat removing duct 22 and to cool and liquify refrigerant in the condenser duct or passage 21. The liquified refrigerant enters the dryerfilter 38 and flows, under the control of restrictor tube 39, through the web means 26 into the inlet 32 of the evaporator or refrigerant expansion duct means 27 and 28 wherein it absorbs heat from chamber 11 of cabinet and vaporizes. Cool vapor or gaseous refrigerant leaves the evaporator by way of the return duct 33 and is conducted along the second portion 24 of the roll-forged member back into the compressor within casing 20 through a suitable connection between the roll-forged member and this casing. It will be noted that I have formed both the duct 31 and the refrigerant return duct 33 in close side by side proximity or relationship in web 26 and through the major part of their lengths in portion 24 of the roll-forged member. The restrictor tube 39 within elongated duct 31 is thus disposed in metal to metal contact with the cool refrigerant return duct 33 to provide a heat exchanger therebetween. This is a novel and important feature in the present apparatus and cools liquid refrigerant directed by restrictor tube 39 to the evaporator and also aids in insuring that the refrigerant returning to the compressor will be vaporlzed. The refrigerating system may be cyclically operated by a su1table temperature responsive thermostatic control device as is conventionalin the art.

The manner and method herein disclosed of providing a refrigerant restrictor or control for use with a plate like roll-forged combined evaporator and condenser forming member is economical, of low manufacturing cost and permits a portion of the member, through which a capillary tube extends, to be bent without danger of pinching the restrictor tube closed. My mvention serves to render the use of roll-forged combined element forming members in refrigerating systems practical and without rejects or waste of these members. My improved structure provides for the conduction of condensed liquified refrigerant from one portion of a unitary combined element forming roll-forged member of a refrigerating system to another remote portion thereof without evaporation in its course of travel whereby to confine absorption of heat to the heat absorber or evaporator element or portion of the member. While the restrictor is a capillary tube separate from the roll-forged member it is throughout the greater part of its length within and concealed by the member and in good heat exchange relationship with a desired part thereof. It should be apparent from this that I have utilized all the advantages of a one piece roll-forged plate member and a separate capillary tube to provide a simphfied and economical refrigerating system.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. In a refrigerating system, a one piece roll-forged plate member having a plurality of passages formed therein, said member comprising a first portion with the passages therein forming refrigerant expansion duct means to provide an evaporator in said system and a second portion spaced from said first portion and connected thereto by web means formed integrally with said portions, one of the passages within said second portion of said roll-forged plate member providing a refrigerant condenser in said system, another of the passages within said second portion of said member forming an elongated duct extending through said web means and normally connecting an outlet end of said condenser passage to 6 an inlet of said expansion duct means, a part of said second portion of the roll-forged plate member with a segment of said elongated duct therein at the outlet end of said condenser being cut away to expose an end of said elongated duct and the outlet end of said condenser passage, a tube separate from said member inserted into the exposed end of said elongated duct and extending therethrough beyond said web means with its one end terminating at a point adjacent the inlet of said evaporator expansion duct means, the other end of said separate tube communicating with the exposed outlet end of said condenser passage, meansfor sealingly bonding walls of said elongated duct to said tube and said other end of said tube to the outlet end of said condenser passage, and the inside diameter of said separate tube being of substantially capillary size as compared to the crosssectional area of said refrigerant condensing passage and said refrigerant expansion duct means for controlling the flow of refrigerant from said condenser to said evaporator.

2. A member of a refrigerating system as defined by claim 1 wherein the first pO-rtion of the member is disposed within a chamber of a refrigerator cabinet and is bent to provide walls of a freezing compartment therein and the second portion of the member has a part thereof spaced from the cabinet back wall to form :a vertical air flue therebetween. V

3. In a refrigerating system, a one piece roll-forged plate member having a plurality of passages formed therein, said member comprising a first portion with the passages therein forming refrigerant expansion duct means to provide an evaporator in said system and a second portion spaced from said first portion and connected thereto by webmeans formed integrally with said portions, one of the passages within said second portion of said roll-forged plate member providing a refrigerant condenser in said system, another of the passages within said second portion of said member forming an elongated duct extending through said web means and normally connecting an outlet end of said condenser passage to an inlet of said expansion duct means, a part of said second portion of the roll-forged plate member with a segment of said elongated duct therein at the outlet end of said condenser being cut away to expose :a first end of said elongated duct and the outlet end of said condenser passage, a part of said first portion of the roll-forged plate member with a segment of said elongated duct therein at the inlet to said evaporator expansion duct means being cut away to expose a second and a third end of said elongated duct, a tube separate from said member inserted into said first exposed end of said elongated duct and extending therethrough beyond said web means through said second exposed duct end with its one end communicating with said third exposed end of said elongated duct, the other end of said separate tube communicating with the exposed outlet end of said condenser passage, means for sealingly bonding said one end of said tube to said third exposed end of said elongated duct and said other end of said tube to the outlet end of said condenser passage, and the inside diameter of said separate tube being of substantially capillary size as compared to the cross-sectional area of said refrigerant condensing passage and said refrigerant expansion duct means for controlling the flow of refrigerant therebetween.

4. In a refrigerating system, a one piece roll-forged plate member having a plurality of passages formed therein, said member comprising a first portion with the passages therein forming refrigerant expansion duct means to provide an evaporator in said system and a second portion spaced from said first portion and connected thereto by web means formed integrally with said portions, one of the passages within said second portion of said rollforged plate member providing a refrigerant condenser in said system, another of the passages within said second portion of said member forming an elongated duct extending through said web means and normally connecting 7 an outlet end of said condenser passage to an inlet of said expansion duct means, still another of the passages within said second portion fo said member forming a refrigerant return conduit also extending through said web means and connected to an outlet end of said expansion duct means, a part of said second portion of the roll-forged plate member with a segment of said elongated duct therein at the outlet end of said condenser being cut away to expose an end of said elongated duct and the outlet end of said condenser passage, a capillary tube separate from said member inserted into the exposed end of said elongated duct and extending therethrough beyond said web means with its one end terminating at a point adjacent the inlet of said evaporator expansion duct means, the other end of said capillary tube communicating with the exposed outlet end of said condenser passage, means for sealingly bonding walls of said elongated duct to said tube and said other end of said tube to the outlet end of said condenser passage whereby the separate capillary tube constitutes a means for controlling the flow of refrigerant from said condenser to said evaporator, and said capillary tube extending along and in close proximity to said refrigerant return conduit within said roll-forged member so as to be in heat exchange relationship therewith throughout a substantial portion of its length.

5. A member of a refrigating system as defined by claim 4 wherein the first portion of the member is disposed within a chamber of a refrigerator cabinet and is bent to provide walls of a freezing compartment therein and the second portion of the member has a part thereof spaced from the cabinet back wall to form a vertical air flue there-' between.

, 6. In a refrigerating system, a one piece roll-forged plate member having a plurality of passages formed therein, said member comprising a first portion with the passages therein forming refrigerant expansion duct means to provide an evaporator in said system and a second portion spaced from said first portion and connected thereto by web means formed integrally with said portions, one of the passages within said second portion of said roll-forged plate member providing a refrigerant condenser in said system, another of'the passages within said second portion of said member forming an elongated duct extending through said web means and normally connecting an outlet end of said condenser passage to an inlet of said expansion duct means, still another of the passages within said second portion of said member forming a refrigerant return conduit also extending through said web means and connected to an outlet end of said expansion duct means in said first portion of said member, a part of said second portion of the roll-forged plate member with a segment of said elongated duct therein at the outlet end of said condenser being cut away to expose an end of said elongated duct and the outlet end of said condenser passagepa capillary tube separate from said member inserted into the exposed endofsaid elongated duct and extending therethrough beyond said web means with its one end terminating at a point adjacent the inlet of said evaporator expansion duct means,

' the other end of said separate tube communicating with the exposed outlet end of said condenser passage, means for sealingly bonding walls of said elongated duct to said tube and said other end of said tube to the outlet end of said condenser passage whereby the separate capillary tube controls the flow of refrigerant from said condenser to said evaporator, and said capillary tube extending along and in close proximity to said refrigerant return conduit within said roll-forged member so as to be in intimate heat exchange therewith throughout a greater part of its length.

' 7. In combination, a refrigerator cabinet provided with a food storage chamber therein and having a one piece roll-forged, plate member of a refrigerating system associated therewith, said plate member having a plurality of passages formed therein, said member comprising a first portion with the passages therein forming refrigerant expansion duct means to provide an evaporator in said system and a second portion spaced from said first portionand connected thereto by a single web formed integrally with said portions, one of the passages within said second portion of said roll-forged plate member providing a refrigerant condenser in said system, another of the passages within said second portion of said member forming an elongated duct extending through said single web and normally connecting an outlet end of said condenser passage to an inlet of said expansion duct means, a part of said second portion of the roll-forged plate member with a segment of said elongated duct therein at the outlet end of said condenser being cut away to expose an end of said elongated duct and the outlet end of said condenser passage, a tube separate from said member inserted into the exposed end of said elongated duct and extending therethrough beyond said single web with its one end terminating at a point adjacent the inlet of said evaporator expansion duct means, the other end of said separate tube communicating with the exposed outlet end of said condenser passage, means for sealingly bonding walls of said elongated duct to said tube and said other end of said tube to the outlet end of said condenser passage, the inside diameter of said separate tube being of substantially capillary size as compared to the cross-sectional area of said refrigerant condensing passage for controlling the flow of refrigerant from said condenser to said evaporator, and said first portion of said member being disposed within said food storage chamber for cooling same and said second portion of said member having a, part thereof spaced from the outer surface of an upright wall of said cabinet to form an air flue therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 2,231,162 I- lintze Feb. 11, 1941 

